Apparatus for handling plates to be



March 10, 1964 R. KA APPARATUS FOR HAND ULEN LING PLATES TO BE PREPARED AS PRINTING FORMS Filed July Fig. 2

Roert Kaulen flvww titted rates This invention relates to apparatus for handling relief printing plates which are to be prepared as printing forms,

particularly for the coating of such plates by means of a solution.

The production of plates of zinc or the like intended, for example, to be used as printing blocks, comprises first providing them with a so-called etching ground, which may consist of a resin solution. For the purpose of coating it, the plate is dipped into a container forming a bath holding the solution. After removal of the plate from the bath, it is'introduced into a drying cupboard where it is subjected to the action of heat for drying purposes. The plate is then coated with a photo-sensitive solution, which may be done in a centrifugal operation. The plate is dipped in the bath container and brought to the drying cupboard by hand. Since plates may be of considerable size and weight (for example having a length of one meter or more), manual handling is not only complicated but also entails the risk of striking and damaging the applied coating, for example, the etching ground, through mechanical effects, such as scratches and the like, which can afterwards be disagreeably noticeable in the completed printing form.

The invention has the object of providing apparatus suitable for eliminating the disadvantages described in handling plates. In apparatus according to the invention a plate is suspended to be slidable on a transport device above the container or bath holding the solution. In addition, the container is adapted to be raised to the height of the plate and lowered again from that height. Sources of heat, for example, radiation lamps or the like, are connected to the vertically adjustable container, their zone of action being directed towards the plate surfaces. In this way continuous uniform coating of the plates with the solution or the like can advantageously be achieved with the immediate application of a drying operation. The plates to be treated are suspended and moved on a transport device; they remain unchanged on the transport device for the immersion operation. For the immersion operation the container holding the solution bath is moved upwards until the plate is completely immersed in the bath, whereupon the container is lowered again. The sources of heat disposed on the upper end of the vertically adjustable container produce uniform drying of the coating applied, without running, progressively as the plate is freed from the bath liquid. As soon as the plate is free again, it is transported in the direction of the plane of the plate. At the same time the plate can run through a prearranged path for the purpose of further drying before the plate is removed for further treatment from the transport device. Through the apparatus according to the invention there is a considerable saving of space and time, and output is increased.

The drying of the plate coated with the solution can be further promoted by directing a current of air onto the surface of the plate. For this purpose supporting screens carrying the sources of heat are advantageously disposed at an angle to the center of the container, while their bottom part engages over the edge of the container. A slit through which the air can enter from below is formed between the said supporting screens and the container edges, this slit running along the edge. The sources carriages,

3,124,485 Patented Mar. 10, 1964 of heat produce a natural upward airflow by which the air is sucked out of the space and moved past the plate surface. If fine screens are disposed between the container edge and the retaining plate, the air will at the same time be filtered before reaching the surface of the plate on which the coating is to be dried. Dust particles are thus kept away from it.. In some cases, blast air can also be additionally employed.

It is advantageous to select a container length surficiently great to enable a plurality of plates disposed side by side or one behind the other to be immersed in the bath. Each plate can be moved in the direction of the plane of the plate above the container. However, each plate may also be moved transversely to the direction of the plane of the plate. In many cases coating on both sides is desirable and advantageous. The arrangement may also be such that two plates located close against one another back-t-o-back may be combined to form a unit, and immersed as a unit in the container.

The transport device may be constructed in various ways. Advantageously it has a length of rail on which rollers or carriages are slidable. The plates may be suspended bymeans of hooks or the like on these rollers or The rail is advantageously endless so that the rollers, carriages, or the like can be circulated back to the starting position. The rails run in a straight line along the bath container and also along another stretch serving for drying.

One form of apparatus according to the invention is illustrated in the accompanying drawings, wherein:

FIG. 1 shows apparatus according to the invention in end elevation and partly in cross-section;

FIG. 2 shows the apparatus of FIG. 1 in side elevation, and

FIG. 3 illustrates diagrammatically a plan of a complete installation incorporating apparatus according to the invention on a smaller scale.

For the purpose of continuous coating with simultaneous drying of a plate 1, there is provided a transport device 2 which is advantageously constructed as a suspension track. The transport device may have a rail 3, for example, of inverted T section, on the lower flange 4 of which a carriage 5 can slide, being supported on the flanges of the rail by means of rollers 6. Hooks 7 depending from the carriage 5 engage holes 8 in the plate 1 and serve to suspend the latter; At a suitable point below the transport device 2 is situated a container 9 which holds the solution ill, for example a resin solution suitable for forming an etching ground, or a photo-sensitive solution or the like. The container 9 is mounted for vertical adjustment. This is advantageously done by hydraulic means, for which purpose the container is provided, in a known manner, with one or more cylinders 11 into each of which a stationary piston 12 projects. The pressure medium is supplied at an inlet 12:.

Sources of heat 14-, for example infra-red lamps, are disposed on the upper longitudinal edges of the container 9, their zone of action being directed onto the surface of the plates 1. The sources of heat are carried by supporting screens 15 disposed at an angle to the longitudinal median plane of the container and hinged at the lower edge as at 15 to the outer edge of the adjacent top flange 10 The uppermost sources of heat may be disposed as close as possible to the plates 1. The bottom parts of the screens 15 are spaced from edges of the container 9 to a greater or lesser extent so that a slit is formed in the flange 1t) through which air can enter the spaces between the screens and the plate, as shown by the arrows 16. Suction is produced by convection and produces a current of air directed upwards over the plate. The slits running along the upper edge of the container 9 are preferably closed by very fine screens 1'7 whereby the flowing air is filtered.

The screens 15 carrying the lamps 14 may be adjustable on their hinges 15 in angular position in relation to the container 9. A hood 18 is provided to suck off the vapors above the vertically adjustable container 9.

From the plan shown in FIG. 3 it can be seen that the rail 3 forms an endless loop. Each pair of rollers 6 may be interconnected to form a rigid carriage 19, while the rollers may be connected to the carriage, i.e. the con necting rod, by means of universal joints. The carriages 19 not in use slide on the rail 3 to be returned to the starting point for the treatment of the plates.

It is advantageous to make the container 9 of such length that more than one plate can be simultaneously immersed in the liquid bath. The example illustrated shows a possible arrangement for immersing three plates simultaneously. The procedure is for the plates to be hung on the transport device at point 2% Thereupon the plates are moved to a position above the container 9. The latter is then lifted hydraulically so that the plates are immersed in the liquid bath. During the subsequent lowering of the container the sources of heat 14, and the air flowing through very fine screens 17, have the effect of accelerating the drying operation. As soon as the container 9 has reached its lowermost position, the three coated plates can be moved onto position 21 where the plates remain during the immersion operation for the next following plates. At the point 22 the transported plates are detached individually and passed on for further treatment. The rollers 5, 6 and carriages 19 pass back along the return length of the rail to the starting point 20.

Instead of the T-rail illustrated, any other suitable construction of a suspension track may alternatively be used. In addition, the installation may be so constructed that the plates are movable transversely of the plane of the plates. The container 9 should then be lowered to such an extent that the upper edge of the screens 15 lie below the lower edges of the plates.

What is claimed is:

1. Apparatus for coating a plate to be prepared as relief printing forms by immersion into a solution, corrprising a transport device, means for suspending a plate from said transport device, a solution container over which said transport device moves said plate, means for raising and lowering said container completely to immerse the plate, laterally offset flanges on the upper edges of the container, said flanges having outer edges, supports carried at said outer edges of said offset flanges, and infrared lmnps carried by said supports and movable with said container, said flanges being provided with screened openings between said support-s and said container to provide apertures for upwardly flowing air drafts.

2. The structure of claim 1 wherein said supports are pivotally mounted on said outer edges of said offset flanges and are adiu'stably inclined inwardly toward the longitudinal median plane of said container, extending inwardly at their tops over the side edges of said container in close juxtaposition to said plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,068,367 Bohannon Ian. 19, 1937 2,647,488 Shive Aug. 4, 1953 2,901,378 Kernpen Aug. 25, 1959 FOREIGN PATENTS 1,237,675 France June 20, 1960 280,495 Switzerland May 1, 1952 

1. APPARATUS FOR COATING A PLATE TO BE PREPARED AS RELIEF PRINTING FORMS BY IMMERSION INTO A SOLUTION, COMPRISING A TRANSPORT DEVICE, MEANS FOR SUSPENDING A PLATE FROM SAID TRANSPORT DEVICE, A SOLUTION CONTAINER VOER WHICH SAID TRANSPORT DEVICE MOVES SAID PLATE, MEANS FOR RAISING AND LOWERING SAID CONTAINER COMPLETELY TO IMMERSE THE PLATE, LATERALLY OFFSET FLANGES ON THE UPPER EDGES OF THE CONTAINER, SAID FLANGES HAVING OUTER EDGES, SUPPORTS CARRIED AT SAID OUTER EDGES OF SAID OFFSET FLANGES, AND INFRARED LAMPS CARRIED BY SAID SUPPORTS AND MOVABLE WITH SAID CONTAINER, SAID FLANGES BEING PROVIDED WITH SCREENED OPENINGS BETWEEN SAID SUPPORTS AND SAID CONTAINER TO PROVIDE APERTURES FOR UPWARDLY FLOWING AIR DRAFTS. 